Fluid ejection devices may find uses in a variety of different technologies. For example, some printing devices, such as printers, copiers and fax machines, print by ejecting tiny droplets of a printing fluid from an array of fluid ejection mechanisms onto the printing medium. The fluid ejection mechanisms are typically formed on a fluid ejection head that is movably coupled to the body of the printing device. Careful control of the individual fluid ejection mechanisms, the movement of the fluid ejection head across the printing medium, and the movement of the medium through the device allow a desired image to be formed on the medium.
The fluid ejection mechanisms typically are fabricated on a semiconductor die that forms part of the fluid ejection head, and are controlled by control signals from off-printhead circuitry. To allow the control signals to reach the fluid ejection mechanisms, the fluid ejection die includes one or more electrical contacts for connecting the die to electrical connectors leading to the control circuitry. These contacts (or contact pads) are typically formed on the same surface of the die as the openings of the fluid ejection mechanisms.
Due to the proximity of the contact pads to the openings of the fluid ejection mechanisms on the die surface, it may be possible for fluid to contaminate the contact pad region of the fluid ejection head die during device use. This may cause electrical shorts to form between adjacent leads, and thus may degrade printhead performance.
The present invention provides a mold configured to be coupled to a fluid ejection head die to allow a protective material to be molded around a plurality of contact pads on the die. The mold includes a molding surface configured to cover the contact pads, wherein the molding surface is configured to support and shape the protective material during molding, and at least one side extending away from the molding surface, wherein the side is configured to contain the protective material during molding.